The present invention relates to a system to mechanically destroy printer toner cartridges and reclaim their constituent materials under a water shielded environment to provide a safer and more environmentally friendly recycling system. More specifically an economical system is disclosed that provides greater protection from possible fire or explosion and releases less irritating or possibly harmful airborne contamination than the currently available systems.
Printer toner cartridges are made from materials that are economically recyclable. Currently, one method used to recycle the cartridges demolishes them by grinding and the resultant regrind material is separated or sorted into several salvage categories. The material categories generally include structural and non-structural plastics, toner, steel and aluminum. When separated into these categories, the salvaged materials can generally be sold to various recyclers at a price sufficient to economically support the salvage operations.
Recycling of printer toner cartridges is moderately hazardous due to two conditions that can result primarily from handling or processing toner during the recycling operations. Toner consists of a combination of carbon and certain plastics reduced to a very finely divided powder. Fine powder, if it is flammable, can become airborne and when airborne it can be more easily ignited and it can be inhaled by exposed personnel.
One hazard results from the toner being flammable, or explosive. This hazard requires the toner to be exposed to a suitable ignition source while in a combustion supporting atmosphere. This is most easily accomplished when airborne and finely ground materials are subject to becoming airborne when disturbed.
The toner materials are believed to be no-toxic to humans, however, they may become airborne as stated above. It has been shown that breathing even seemingly inert materials that are finely ground may result in various undesirable health issues. Therefore, a second hazard can result if operators or other personnel are exposed to airborne materials released from the handling and grinding operations.
Currently, some processors have ignored the problems (they believe the risks to be acceptable). Other processors, who want to accept less risk, have operated their processes in an isolated area or in some form of inert atmosphere.
It is an objective of this invention to describe a novel non-flammable fluid based method of recycling that is safe and that is more environmentally friendly and that can be more economically implemented than existing recycling systems. It is understood that the method described may have many applications and that describing it for recycling printer toner cartridges is for illustration purposes and is not intended as a limit of its utility.
This invention relates to improvements in the art of safely recycling products, that contain certain types of hazardous materials, by smashing, shredding, grinding and so forth. By way of example, it is desired to demolish printer toner cartridges by grinding. The cartridges may contain various amounts of toner which may be hazardous. The toner could become airborne and, under certain conditions, ignite and cause a fire or explosion or be inhaled by personnel, during the processing.
The present invention uses water or other suitable non-flammable fluid to suppress the chance of fire or explosion. While the description uses water as the fluid of choice, it is understood that other non-flammable fluids may be preferred for certain applications.
The present invention includes the use of mostly commercially available materials and equipment, which are so arranged and configured as to achieve the desired objective. The basic functions are performed by the following elements:
(1) Infeed hopper and conveyor
(2) Combination shredder/grinder
(3) Oscillating screen
(4) Flotation separator and wiper(s)
(5) Outfeed conveyor
(6) Ferrous metal separators
(7) Non-ferrous metal separator
(8) Non-metallic separator
(9) Material driers
(10) Storage/transport containers
These functional elements may be enclosed in a suitable chamber that contains moisture released in the process and isolates personnel from any unnecessary exposure. The containment chamber is preferably constructed from strong and fireproof materials that are not degraded by water or other fluid selected for use in the process. The process starts with printer cartridges dumped into the infeed hopper and finishes with materials separated by type and size being dumped into suitable storage/transport containers.